The common-rail system has been applied for a long time in the fuel injection system of engines. The structure of the common rail for fuel injection is greatly constrained because it needs to withstand a high pressure. Since a cylindrical structure can withstand a higher pressure than other structures, the cylindrical structure is adopted for almost all existing common rails for fuel injection.
As the standards for exhaust emission in countries all over the world are increasingly becoming more strict, more requirements are put forward for the urea spraying system used for exhaust treatment. How to control the pressure in the urea spraying system is a common technical problem in the industry.
In addition, for exhaust treatment of a high-power engine, the pipeline of the urea spraying system is often very long and the pressure loss is relatively great, and therefore it is necessary to provide a common rail which can stabilize the system pressure, the application of the common rail, a urea spraying system having the common rail, and a control method therefor.